Dice the onion and smash the garlic. Sautee the onion and garlic until onion begins to soften. Add mushrooms and saute until onion is soft and golden. Add tomatoes, paste, stock, brandy, marjoram, parsley (in that order) and pepper to taste. Mix well, and simmer on low heat for thirty minutes, stirring intermittently. Cut mock-chicken (thoroughly thawed, if necessary) into bite-sized pieces and add to the sauce. Simmer for a few more minutes until warmed through.
Serve over pasta (I prefer linguini here).
(Note on mock-chicken: I prefer Garden burger’s Flame Grilled Chik'n patties for this dish, but it has a strong flavor, not entirely like chicken, that may not suit everyone's palate, so feel free to substitute any commercial mock-chicken or to make your own. Frozen and thawed tofu, for example, makes an excellent substitute with an authentic texture, but has no flavor of its own.)